A stripping solution for thick photoresist and a preparation method thereof

Abstract

The application relates to the technical field of photoresist technology, in particular to a stripping liquid for thick photoresist and a preparation method thereof.According to mass fractions, the stripping liquid for thick photoresist comprises a solvent system 30-40 parts, active ingredients 20-30 parts, a modifier 3-7 parts and a stabilizer 0.5-1 part, wherein the stabilizer is hydroxyethyl cellulose; the active ingredients comprise a cyclodextrin-stannous octanoate complex and a polyferric silicate solution, and the mass ratio of the polyferric silicate solution to the cyclodextrin-stannous octanoate complex is (3-5):1.The stripping liquid for thick photoresist and the preparation method thereof can solve the problem that ordinary stripping liquids cannot strip thick photoresist in the prior art.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of photoresist stripping agents, in particular to a stripping liquid for thick photoresist stripping agents and a preparation method. BACKGROUND

[0002] In the fields of semiconductor manufacturing, printed circuit board processing and precision electronic device production, photoresist stripping agents are key materials for pattern transfer, and the subsequent stripping process directly affects the yield and performance of products. As the core consumables of the process, photoresist stripping liquids need to efficiently remove photoresist stripping agents while avoiding corrosion or damage to the substrate, so the optimization of their performance has always been the focus of industry research.

[0003] Common photoresist stripping liquids include acidic, neutral and alkaline solutions. Acidic solutions are suitable for processes without metal layers, can effectively remove photoresist stripping agents without damaging the underlying layer; neutral solutions are used in processes involving pH-sensitive layers, can maintain pH balance and avoid damage; alkaline solutions are used to strip photoresist stripping agents under high baking conditions, and have good decomposition effect on hardened photoresist stripping agent materials due to long-term baking.

[0004] Thick photoresist stripping agents have a thick coating, high intermolecular cross-linking density, and a hard three-dimensional network structure formed after high-temperature baking, and have a large bonding force with the substrate. Conventional stripping liquids are difficult to penetrate and damage the bonding between the thick photoresist stripping agent and the substrate. Therefore, for thick photoresist stripping agents, the conventional stripping method is to extend the stripping time, increase the temperature and concentration of the stripping liquid, but this will affect the production capacity and yield, increase the production cost, intensify the corrosion of the substrate, and also affect the product yield and reliability. SUMMARY

[0005] The application provides a stripping liquid for thick photoresist stripping agents and a preparation method to solve the problem that ordinary stripping liquids in the related art cannot strip thick photoresist stripping agents.

[0006] In a first aspect, a stripping liquid for thick photoresist stripping agents is provided, which comprises, by mass fraction:

[0007] 30-40 parts of a solvent system, 20-30 parts of an active ingredient, 3-7 parts of a modifier, and 0.5-1 part of a stabilizer, wherein the stabilizer is hydroxyethyl cellulose.

[0008] The active ingredient includes a cyclodextrin-stannous octanoate complex and a polysilicic acid iron solution, and the mass ratio of the polysilicic acid iron solution to the cyclodextrin-stannous octanoate complex is (3-5):1.

[0009] Preferably, the preparation method of the cyclodextrin-stannous octanoate complex comprises:

[0010] The β-cyclodextrin is added to deionized water at a mass ratio of 1:10, heated to 60℃, and stirred at a speed of 200r / min until dissolved, then stannous octoate is added and the reaction is continued for 3h, the solution is cooled to room temperature, distilled under reduced pressure, filtered with a 0.45μm filter, and freeze-dried to obtain a cyclodextrin-stannous octoate complex;

[0011] The molar ratio of the β-cyclodextrin to stannous octoate is 2:1.

[0012] Preferably, the active ingredient also includes sodium citrate, and the mass ratio of the sodium citrate to the iron polysilicate solution is 1:5.

[0013] Preferably, the preparation method of the iron polysilicate solution is as follows:

[0014] Dissolve the iron sulfate in deionized water and stir until completely dissolved to obtain an iron sulfate solution, and the mass ratio of the iron sulfate to the deionized water is 1:10.

[0015] Dissolve the sodium silicate in deionized water, add concentrated sulfuric acid dropwise to adjust the pH to 2-3, stir until uniform, and then stand for 30min to form a polysilicic acid solution, and the mass ratio of the sodium silicate to the deionized water is 1:8.

[0016] Slowly pour the polysilicic acid solution into the iron sulfate solution under stirring, the reaction temperature is 50℃, and the stirring is continued for 2h; after the reaction is completed, the solution is cooled to room temperature to obtain an iron polysilicate solution, and the mass ratio of the polysilicic acid solution to the iron sulfate solution is 2:1.

[0017] Preferably, when the polysilicic acid solution is slowly poured into the iron sulfate solution, the polysilicic acid solution is added at a rate of 2 drops / s and the rotation speed is 150r / min.

[0018] Preferably, the modifier includes polydopamine, glycyrrhizic acid, hyaluronic acid, and deionized water at a mass ratio of 4:(1-2):1:100, and the preparation method of the polydopamine includes:

[0019] Add dopamine hydrochloride to a Tris-HCl buffer solution with a pH of 8.5, stir at room temperature for 24h to obtain a polydopamine solution, dialyze the polydopamine solution through a dialysis bag for 48h, and freeze-dry to obtain polydopamine, the mass-volume ratio of the dopamine hydrochloride to the Tris-HCl buffer solution is 2g:1L, and the molecular weight cut-off of the dialysis bag is 8000-14000.

[0020] Preferably, the solvent system includes dimethyl sulfoxide and polyethylene glycol, and the mass ratio of the polyethylene glycol to the dimethyl sulfoxide is 1:(8-10).

[0021] Preferably, the polyethylene glycol is industrial-grade polyethylene glycol 400.

[0022] In a second aspect, a preparation method is provided for preparing the stripping solution for thick photoresist etching resist according to any one of the above, comprising the following steps:

[0023] The cyclodextrin-stannous octoate complex in the active ingredient is added to the solvent system, stirred at room temperature at a speed of 150 r / min for 30 min, then the iron polysilicate solution is continuously added, and stirred for 30 min;

[0024] The modifier is continuously added and stirred for 1 h, then the hydroxyethyl cellulose is added, and stirred for 30 min to obtain the stripping solution for thick photoresist etching resist.

[0025] The technical solutions provided in the application have the following beneficial effects:

[0026] The application provides a stripping solution for thick photoresist etching resist and a preparation method thereof. The iron polysilicate in the active ingredient is enriched on the photoresist surface through electrostatic adsorption, forms a porous structure to promote the penetration of the solvent system, and the cyclodextrin-stannous octoate complex targets the stannous octoate to the photoresist crosslinking site through the packaging effect of cyclodextrin to catalytically decompose the ester bond, so that it can more effectively act on the thick photoresist etching resist. The carboxymethyl cellulose as a stabilizer prevents the agglomeration of iron polysilicate through steric hindrance effect, prolongs the residence time of the stripping solution on the vertical surface, and significantly improves the stripping effect of the deep part of the thick photoresist, so that the problem that the ordinary stripping solution in the related art cannot strip the thick photoresist etching resist can be solved. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0028] Figure 1 The flow chart of the preparation method of the stripping solution for thick photoresist etching resist provided in the application. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the application clearer, the technical solutions in the embodiments of the application will be described clearly and completely in the following with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without any creative effort belong to the scope of protection of the application.

[0030] Referring to Figure 1 As shown in the drawings, the application provides a stripping solution for thick photoresist and a preparation method thereof.

[0031] Embodiment 1

[0032] The preparation method of the stripping solution for thick photoresist provided by the embodiment comprises the following steps:

[0033] 5g of the cyclodextrin-stannous octoate complex in the active ingredient is added to 35g of the solvent system, stirred at a speed of 150r / min for 30min at room temperature, then 20g of the iron polysilicate solution is continuously added and stirred for 30min;

[0034] 5g of the modifier is continuously added and stirred for 1h, then 0.5g of the hydroxyethyl cellulose and 4g of the sodium citrate are added, and the stripping solution for thick photoresist is obtained after stirring for 30min.

[0035] The solvent system comprises 3g of industrial-grade polyethylene glycol 400 and 32g of dimethyl sulfoxide.

[0036] The modifier comprises 0.189g of polydopamine, 0.064g of glycyrrhizic acid, 0.047g of hyaluronic acid and 4.7g of deionized water, wherein the preparation method of the polydopamine comprises:

[0037] 1g of the dopamine hydrochloride is added to 500mL of the Tris-HCl buffer solution with a pH of 8.5, stirred at room temperature for 24h to obtain a polydopamine solution, the polydopamine solution is dialyzed through a dialysis bag (molecular weight cut-off: 8000-14000) for 48h, and then freeze-dried to obtain the polydopamine.

[0038] The preparation method of the cyclodextrin-stannous octoate complex is as follows:

[0039] 10g of β-cyclodextrin is added to 100mL of deionized water, heated to 60℃, and stirred to dissolve at a speed of 200r / min, then 1.785g of stannous octoate is added, and the stirring reaction is continued for 3h, the solution is cooled to room temperature, distilled under reduced pressure, filtered through a 0.45μm filter, and then freeze-dried (-50℃, 12h) to obtain the cyclodextrin-stannous octoate complex.

[0040] The operation conditions of the reduced pressure distillation are as follows: the pressure is adjusted to 20mmHg, the distillation temperature is 50℃, and the distillation is carried out at a distillation rate of 30mL / min until the remaining liquid volume of the system reaches 10% of the initial volume.

[0041] The preparation method of the iron polysilicate solution is as follows:

[0042] Dissolve 5 g of iron sulfate in 50 g of deionized water, stir until completely dissolved, to obtain an iron sulfate solution;

[0043] Dissolve 5 g of sodium silicate in 40 g of deionized water, add concentrated sulfuric acid dropwise to adjust the pH to 2, stir uniformly, and then stand for 30 min to form a polysilicic acid solution;

[0044] Slowly pour the 40 g of polysilicic acid solution prepared above into the 20 g of iron sulfate solution under stirring (speed of 150 r / min), the dropwise adding rate of the polysilicic acid solution is 2 drops / s, the reaction temperature is 50°C, and the stirring reaction is continued for 2 h; after the reaction is completed, cool to room temperature to obtain an iron polysilicate solution.

[0045] Example 2

[0046] The difference between this embodiment and Example 1 is that sodium citrate is not included in the active ingredient.

[0047] Example 3

[0048] The difference between this embodiment and Example 1 is that sodium citrate is not added to the active ingredient, and the amount of modifier added is 3 g.

[0049] Example 4

[0050] The preparation method of the stripping solution for thick photoresist resistors provided in this embodiment includes the following steps:

[0051] Add 5 g of cyclodextrin-stannous octanoate complex in the active ingredient to 30 g of the solvent system, stir at room temperature at a speed of 150 r / min for 30 min, then continue to add 15 g of iron polysilicate solution, and stir for 30 min;

[0052] Continue to add 3 g of modifier and stir for 1 h, then add 0.5 g of hydroxyethyl cellulose and 3 g of sodium citrate, and stir for 30 min to obtain the stripping solution for thick photoresist resistors.

[0053] The solvent system includes 3 g of industrial-grade polyethylene glycol 400 and 27 g of dimethyl sulfoxide.

[0054] The modifier includes 0.116 g of polydopamine, 0.056 g of glycyrrhizic acid, 0.028 g of hyaluronic acid, and 2.8 g of deionized water, wherein the preparation method of polydopamine is consistent with that of Example 1.

[0055] The preparation method of the cyclodextrin-stannous octanoate complex is consistent with that of Example 1.

[0056] The preparation method of the iron polysilicate solution is:

[0057] Dissolve 5 g of iron sulfate in 50 g of deionized water, stir until completely dissolved, to obtain an iron sulfate solution;

[0058] Dissolve 5 g of sodium silicate in 40 g of deionized water, add concentrated sulfuric acid dropwise to adjust the pH to 3, stir uniformly and stand for 30 min to form a polysilicic acid solution;

[0059] Slowly pour the above-prepared 40 g of polysilicic acid solution into 20 g of ferric sulfate solution under stirring (speed of 150 r / min), the dropwise adding rate of the polysilicic acid solution is 2 drops / s, the reaction temperature is 50°C, and the stirring reaction is continued for 2 h; after the reaction is completed, the temperature is cooled to room temperature to obtain a ferric polysilicate solution.

[0060] Example 5

[0061] The preparation method of the stripping solution for thick photoresist resistors provided in this example includes the following steps:

[0062] Add 5 g of cyclodextrin-stannous octoate complex in the active ingredient to 40 g of the solvent system, stir at room temperature at a speed of 150 r / min for 30 min, then continue to add 25 g of ferric polysilicate solution, and stir for 30 min;

[0063] Continue to add 7 g of modifier and stir for 1 h, then add 1 g of hydroxyethyl cellulose and 5 g of sodium citrate, and stir for 30 min to obtain the stripping solution for thick photoresist resistors.

[0064] The solvent system includes 3.64 g of industrial-grade polyethylene glycol 400 and 36.36 g of dimethyl sulfoxide.

[0065] The modifier includes 0.264 g of polydopamine, 0.068 g of glycyrrhizic acid, 0.068 g of hyaluronic acid, and 6.6 g of deionized water, wherein the preparation method of the polydopamine is consistent with that of Example 1.

[0066] The preparation methods of the cyclodextrin-stannous octoate complex and the ferric polysilicate solution are consistent with those of Example 1.

[0067] Example 6

[0068] The preparation method of the stripping solution for thick photoresist resistors provided in this example includes the following steps:

[0069] Add 6 g of cyclodextrin-stannous octoate complex in the active ingredient to 30 g of the solvent system, stir at room temperature at a speed of 150 r / min for 30 min, then continue to add 24 g of ferric polysilicate solution, and stir for 30 min;

[0070] Continue to add 5 g of modifier and stir for 1 h, then add 0.8 g of hydroxyethyl cellulose and 4.8 g of sodium citrate, and stir for 30 min to obtain the stripping solution for thick photoresist resistors.

[0071] The solvent system comprises 3.33 g of industrial-grade polyethylene glycol 400 and 26.67 g of dimethyl sulfoxide.

[0072] The modifier comprises 0.189 g of polydopamine, 0.064 g of glycyrrhizic acid, 0.047 g of hyaluronic acid, and 4.7 g of deionized water, wherein the preparation method of polydopamine is consistent with that in Example 1.

[0073] The preparation method of the cyclodextrin-stannous octoate complex and the iron polysilicate solution is consistent with that in Example 1.

[0074] Comparative Example 1

[0075] The difference from Example 1 is that the cyclodextrin-stannous octoate complex in the active ingredient is replaced with an equal amount of stannous octoate, and no polydopamine is added to the modifier.

[0076] Comparative Example 2

[0077] The difference from Example 1 is that the solvent system is replaced with an equal amount of polyethylene glycol (without adding dimethyl sulfoxide), and no polydopamine is added to the modifier.

[0078] Comparative Example 3

[0079] The difference from Example 1 is that the dimethyl sulfoxide in the solvent system is replaced with an equal amount of dimethyl carbonate, and no cyclodextrin-stannous octoate complex is added to the active ingredient, only the iron polysilicate solution and sodium citrate are retained.

[0080] The stripping solution (hereinafter referred to as “stripping solution”) for thick photoresist etching agents prepared in Examples 1-6 and Comparative Examples 1-3 was tested.

[0081] Peeling efficiency test:

[0082] A 4-inch-diameter silicon wafer (0.5 mm thick) was used as the substrate, and an AZ4562 positive thick photoresist etching agent (material) was coated on the surface of the silicon wafer using a spin coater, with a coating thickness of 100 μm. After pre-baking in a 120°C oven for 30 min and cooling to room temperature, the sample was exposed to ultraviolet light using a UV exposure machine (instrument) at 300 mJ / cm 2 After developing in a 2.38 wt% tetramethylammonium hydroxide solution (developer, material) for 1 min and rinsing with deionized water, a test sample containing a cured photoresist was obtained.

[0083] The test sample was immersed in a beaker containing 50 mL of the stripping solution to be tested, and the temperature was set to 50°C. Every 30 s, the test sample was taken out with tweezers, and the surface photoresist residue was observed with a scanning electron microscope after rinsing with deionized water. The time at which the photoresist completely fell off (i.e., the complete stripping time) was recorded.

[0084] Corrosion rate test:

[0085] A 4-inch diameter silicon wafer (0.5 mm thick) and a copper substrate (purity ≥ 99.9%) with a size of 50 mm x 50 mm x 1 mm were used as the base material, washed with deionized water, dried at 60°C for 2 h, and weighed and recorded using an electronic balance (accuracy 0.1 mg, instrument) to obtain the mass of the silicon wafer and the copper substrate before corrosion (m1);

[0086] The silicon wafer and the copper substrate were immersed in a beaker containing 50 mL of the stripping solution to be tested, and the temperature was set to 50°C for 2 h. After the immersion was completed, the silicon wafer and the copper substrate were removed with tweezers, immediately rinsed with deionized water three times to remove the residual stripping solution on the surface, and then placed in a vacuum drying oven at 60°C for 2 h;

[0087] After drying, the samples were cooled to room temperature, and the mass of the silicon wafer and the copper substrate was weighed and recorded again using an electronic balance to obtain the mass after corrosion (m2), and the corrosion rate of the silicon wafer and the copper substrate (μm / h) was calculated according to the following formula:

[0088]

[0089] In the formula, m1 represents the mass of the silicon wafer and the copper substrate before corrosion (g), m2 represents the mass of the silicon wafer and the copper substrate after corrosion (g), ρ is the density of the material (2.33 g / cm 3 for silicon and 8.96 g / cm 3 for copper), S is the surface area of the sample (cm 2 ), and t is the corrosion time (2 h).

[0090] The test results are shown in Table 1.

[0091] Table 1

[0092]

[0093] It can be seen that the effect of Example 1 is better. On the one hand, the solvent system of polyethylene glycol + dimethyl sulfoxide has strong solubility, and the active ingredient synergistically catalyzes the degradation of the photoresist etchant, and the modifier further accelerates the degradation efficiency while forming a protective film, which plays a corrosion inhibition role.

[0094] Specifically, dimethyl sulfoxide has excellent swelling ability, can quickly destroy the three-dimensional network structure of the resist, and enable the cyclodextrin-stannous octanoate complex to quickly penetrate into the photoresist; polyethylene glycol 400 adjusts the viscosity of the system, so that the stripping liquid forms a uniform liquid film on the surface of the thick film, enhances the contact area, and the polyferric silicate is enriched on the surface of the photoresist by electrostatic adsorption to form a porous structure to promote the penetration of the solvent system; in the cyclodextrin-stannous octanoate complex, the cyclodextrin targets the stannous octanoate to the photoresist crosslinking site by encapsulation and catalytically decomposes the ester bond. Carboxymethyl cellulose as a stabilizer, through the steric hindrance effect, prevents the agglomeration of polyferric silicate, and at the same time forms an interpenetrating network structure with hyaluronic acid, prolongs the residence time of the stripping liquid on the vertical surface, and significantly improves the stripping effect of the thick photoresist deep part.

[0095] Compared with Example 1, the corrosion inhibition effect of the active ingredient in Example 2 is slightly weakened, and the stripping rate changes little; compared with Example 1, the active ingredient in Example 3 lacks sodium citrate, and the amount of modifier is reduced, the degradation rate of the photoresist resist is reduced, and the protection of the substrate is insufficient, and the corrosion rate is intensified.

[0096] Examples 4, 5 and 6 adjust the addition amount of each component on the basis of Example 1. In Example 4, the proportion of polyferric silicate in the active ingredient is increased, the stripping time is slightly prolonged, and the corrosion inhibition effect is still stable; in Example 5, the proportion of dimethyl sulfoxide in the solvent system is increased, the solubility is enhanced, and the addition amount of the active ingredient is increased, but the stripping time is not significantly reduced, indicating that the active ingredient in Example 5 is excessive, and the corrosion inhibition effect is stable; in Example 6, the proportion of polyethylene glycol in the solvent system is increased, the solubility is slightly reduced, the proportion of the active ingredient and the modifier is close to that of Example 1, and the complete stripping time is increased, and the corrosion inhibition effect is stable.

[0097] Compared with Example 1, the cyclodextrin-stannous octanoate complex in Comparative Example 1 is replaced by stannous octanoate, and the polydopamine is lacking in the modifier, the catalytic activity is decreased, and the corrosion of the substrate is intensified; compared with Example 1, the solvent system of Comparative Example 2 only has polyethylene glycol 400, and the polydopamine is lacking in the modifier, the complete stripping time is twice that of Example 1, and the corrosion of the silicon wafer and the copper substrate is intensified; in Comparative Example 3, dimethyl sulfoxide in the solvent is replaced by dimethyl carbonate, and the cyclodextrin-stannous octanoate complex is lacking in the active ingredient, the stripping time is multiplied, and the corrosion of the silicon wafer and the copper substrate is more serious.

[0098] The foregoing detailed description of the application has been presented for purposes of illustration and description. Various modifications and changes can be made to these embodiments without departing from the spirit and scope of the application. It is intended that the scope of the application should not be limited by the particular representative embodiments described above.

Claims

1. A stripping solution for thick photoresist, characterized by comprising: a phosphorus compound; a sulfur compound; and water. According to the mass fraction, it comprises: The solvent system 30~40 parts, active ingredient 20~30 parts, modifier 3~7 parts, stabilizer 0.5~1 parts, the stabilizer is hydroxyethyl cellulose; The modifier includes polydopamine, glycyrrhizic acid, hyaluronic acid and deionized water with a mass ratio of 4:(1~2):1:100; The solvent system includes dimethyl sulfoxide and polyethylene glycol, and the mass ratio of polyethylene glycol and dimethyl sulfoxide is 1:(8~10); The active ingredient includes cyclodextrin-stannous octanoate complex and polyferric silicate solution, and the mass ratio of polyferric silicate solution to cyclodextrin-stannous octanoate complex is (3~5):1; The preparation method of the cyclodextrin-stannous octanoate complex comprises: β-Cyclodextrin is added to deionized water at a mass ratio of 1:10, heated to 60℃, stirred and dissolved at a speed of 200r / min, then stannous octanoate is added, and the stirring reaction is continued for 3h. The solution is cooled to room temperature, distilled under reduced pressure, filtered with a 0.45μm filter membrane, freeze-dried to obtain the cyclodextrin-stannous octanoate complex. The molar ratio of β-cyclodextrin to stannous octanoate is 2:

1.

2. The stripping solution for thick photoresist resist according to claim 1, wherein: The active ingredient further comprises sodium citrate, and the mass ratio of sodium citrate to polyferric silicate solution is 1:

5.

3. The stripping solution for thick photoresist etching as described in claim 1, characterized in that, The preparation method of the polyferric silicate solution is: Dissolve ferric sulfate in deionized water, stir until completely dissolved to obtain a ferric sulfate solution, and the mass ratio of ferric sulfate to deionized water is 1:10; Dissolve sodium silicate in deionized water, add concentrated sulfuric acid dropwise to adjust the pH to 2~3, stir uniformly, and then stand for 30min to form a polysilicic acid solution, and the mass ratio of sodium silicate to deionized water is 1:8; Slowly pour the polysilicic acid solution into the ferric sulfate solution under stirring, the reaction temperature is 50℃, and the stirring reaction is continued for 2h; after the reaction is completed, it is cooled to room temperature to obtain a polyferric silicate solution, and the mass ratio of polysilicic acid solution to ferric sulfate solution is 2:

1.

4. The stripping solution for thick photoresist resist according to claim 3, wherein: When the polysilicic acid solution is slowly poured into the ferric sulfate solution, the dropwise adding speed of the polysilicic acid solution is 2 drops / s, and the rotation speed is 150r / min.

5. The stripping solution for thick photoresist resist according to claim 1, wherein: The preparation method of the polydopamine comprises: Dopamine hydrochloride is added to a Tris-HCl buffer solution with a pH of 8.5, and the stirring reaction is carried out at room temperature for 24h to obtain a polydopamine solution. The polydopamine solution is dialyzed through a dialysis bag for 48h, and then freeze-dried to obtain polydopamine. The mass-volume ratio of dopamine hydrochloride to Tris-HCl buffer solution is 2g:1L, and the molecular weight cut-off of the dialysis bag is 8000~14000.

6. The stripping solution for thick photoresist resist according to claim 1, wherein: The polyethylene glycol is industrial-grade polyethylene glycol 400.

7. A production process for producing the stripping solution for thick photoresist according to any one of claims 1 to 6, characterized by, It comprises the following steps: The cyclodextrin-stannous octoate complex in the active ingredient is added to the solvent system, stirred at room temperature at a speed of 150 r / min for 30 min, then the poly ferric silicate solution is continuously added, stirred for 30 min; The modifier is continuously added and stirred for 1 h, then the hydroxyethyl cellulose is added, and the stripping solution for thick photoresist etching agent is obtained after stirring for 30 min.

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